AutoCodes – Lexus – C1554 Lexus

C1554 Lexus Code - Power Source Relay Circuit Malfunction

Quick Answer

The Diagnostic Trouble Code (DTC) will be set when the Power source relay circuit malfunctions. Common causes include Power Steering ECU Fuse, Faulty Power Steering ECU, Power Steering ECU harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: C1554 Lexus indicates Power Source Relay Circuit Malfunction.
Common causes: Common causes include Power Steering ECU Fuse, Faulty Power Steering ECU, Power Steering ECU harness is open or shorted.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 9,828

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Feb 22, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code C1554 Lexus Description

The Diagnostic Trouble Code (DTC) will be set when the Power source relay circuit malfunctions. If the Power Steering ECU detects this Diagnostic Trouble Code (DTC), it shuts off the motor relay circuit (built into the Power Steering ECU) and stops power assist.

OBDII Code C1554 Lexus - Power Source Relay Circuit Malfunction - AutoCodes.com — C1554 Lexus Code - Power Source Relay Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC C1554 Lexus?

Power Steering ECU Fuse
Faulty Power Steering ECU
Power Steering ECU harness is open or shorted
Power Steering ECU circuit poor electrical connection

How to Fix the DTC C1554 Lexus?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

In some vehicles, it is necessary to replace the Power Steering ECU when there is a problem in the power relay because each relay is built into the Power Steering ECU.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C1554 Lexus code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about C1554 Lexus Code

1. What does the OBDII code C1554 mean for a Lexus?

C1554 indicates a Power Source Relay Circuit Malfunction, meaning there is an issue with the power supply to the Electric Power Steering (EPS) system.

2. What are the common symptoms of C1554 in a Lexus?

Typical symptoms include a non-functioning or stiff power steering, the EPS warning light illuminated on the dashboard, and difficulty turning the steering wheel.

3. What causes the C1554 code in a Lexus?

Common causes include a faulty power source relay, damaged or corroded wiring or connectors in the EPS circuit, a blown fuse, or a problem with the EPS control module.

4. Can I drive my Lexus with the C1554 code?

While it may be possible to drive, itâ€™s not recommended as the power steering may not function properly, making the vehicle harder to control and increasing the risk of an accident.

5. How do I diagnose the C1554 code in a Lexus?

Start by checking the power source relay, fuses, and wiring for damage or corrosion. Use a multimeter to verify electrical continuity and inspect the EPS control module for faults.

6. How can I fix the C1554 code in my Lexus?

Repairs may include replacing the power source relay, repairing or replacing damaged wiring or connectors, replacing a blown fuse, or reprogramming or replacing the EPS control module if necessary.

7. Is the C1554 code specific to Lexus vehicles?

While C1554 is commonly associated with Lexus vehicles, it may also appear in other Toyota models with a similar power steering system.

8. How much does it cost to repair the C1554 code in a Lexus?

Repair costs vary depending on the specific issue, but replacing a power source relay typically costs $50-$150, while more complex repairs like replacing the EPS control module can cost $500 or more.

9. Can a weak battery cause the C1554 code in a Lexus?

Yes, a weak or failing battery can cause voltage issues that may trigger the C1554 code. Ensure the battery is fully charged and in good condition before further diagnosis.

10. Will clearing the C1554 code fix the issue?

Clearing the code may turn off the warning temporarily, but it wonâ€™t address the underlying problem. Proper diagnosis and repair are necessary to resolve the issue completely.